| Wheat is one of the most popular food plants that been cultivated in China. While providing food supply it also bring a large number of waste wheat straw yearly. Some old process on waste wheat straw such as burning can rise severe environmental problems. Thus, the exploitation of wheat straw has been becoming more and more concerned in China. Usually the isocyanate adhesive will be chosen in the manufacture of wheat straw panel. However, this kind of panel couldn抰 be widespread, especially in China, for the high cost and the characteristics of the isocyanate. Then the purpose of our research is to develop the qualified wheat straw fiber board with UF resin which is cheaper compared with isocyanate. By the way of using chemical analysis, FT-IR and ESCA, a comprehensive analysis have been focused on the bulk and the surface characters of Asplund defi bated wheat straw, which was the first trying in China. The results show that low pressure, longer time and high pressure, shorter time steam treatment were not found to have a large effect on the chemical composition of wheat straw. However, the steam treated wheat straw contains relatively low extracts. By TO analysis, weight loss of wheat straw was not found at 1 80C. All results reveal that wheat straw fiber may possibly replace wood fiber as raw material of fiber board. The surface of wheat straw fiber can be activated after Asplund defibration, because the cuticle have been removed from the surface and the polarity of the surface have been increased. Through ESCA, an analysis, which studies the element composition and functional groups that exist in different sections and on the surface of wheat straw, attests the above results. This process of Asplund defibration is very helpful to the adhesion between wheat straw fiber and UF resin. An other way to increase the activity of wheat straw fiber is to graft some monomer branched chain into the surface of wheat straw fiber. After plasma treatment, the surface of wheat straw fiber has been activated without any impairment on its bulk property. The new results provide a rationale fundament for developing other wheat straw composition. A study on curing dynamics of UF resin for wheat straw fiber board has been carried out by DSC analysis. By the change of the activation energy and the exotherm, the curing course of UF resin is comprehended further. It provides a rationale basis for technology of wheat straw fiber board manufacture. The qualified wheat straw fiber board with UF resin has made in Lab., which met the requirement of GB/T 11718-1999. The relationship between the properties and the technic parameters has been discussed. According to the particular physic and chemical characters of wheat straw fiber, the process of wheat straw fiber board is different to that of wood fiber 桰ll? board. To meet the nation抯 criteria, compared with wood fiber board, the wheat straw fiber board should have higher quantity of UF resin and mat moisture content, lower hot-pressing temperature. Under a setting of pre ?heating condition, the quality of wheat straw fiber board will be improved with the prolonging of pre ?heating time if the defibration carried on at 16OXD. Similar as wood fiber board, the increase in board抯 density and the extension in hot- pressing time will enhance the quality of the wheat straw fiber board on the setting conditions. In conclusion, wheat straw fiber is a qualified alternative of wood fiber in UF fiber board manufacture. Furthermore, after improving the compatibility wit...
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